At languagehat 10 days ago,
dearieme asked “When last did you see those old abbreviations for Christian names: Wm, Thos?” and I answered, “They were used in Irish telephone directories into the 1990s.”
Since then, I have cracked open a white-pages for the first time in a long time, and found that in fact such abbreviations are found in Irish phone books to this very day. However, they are now intermixed with the full forms. I checked the 2013 book for 02 (that’s nought-two the digits, not O2 the cellphone company), the area-code approximating County Cork. I checked the surname “Murphy”, the most common surname in Ireland (and originally a Cork name) to see what the stats were for various forenames:
I exclude hypocoristics like “Will”, “Joe” from the above table. Some abbreviatable names were only listed in full form and not in abbreviated form (again, excluding hypocoristics like “Art”, “Bart”): Anthony (9), Arthur (3), Bartholemew (1), Benjamin (1), Bridget (3), Christopher (6), Desmond (5), Nicholas (2), Oliver (5), Raymond (4). I don’t know if any of these were formerly abbreviated.
I surmise that abbreviated forms are no longer being added; as new subscribers are enrolled, and existing subscribers die off or move to a new address and get their entry updated, the full form is replacing the abbreviations. I don’t know when this changeover began. It would be too dull even for me to seek out old phonebooks to scrutinise. I recall c.1995 the format changed so that the surname is listed only at the top of the column or when it changes; a ditto dot is used for subsequent entries of people with the same name. Maybe the forename abbreviations were phased out at the same time.
Based on the preceding surmise, one might estimate how old-fashioned a name is by the proportion of abbreviated forms: older people move house less and so have had the same number and phonebook entry since before the changeover. However, this is not a reliable calculation. Consider Margaret, the only female name listed, and one that strikes me as old-fashioned. I surmise most of the Margarets are not young women with the name, but rather the widows of men who died after the changeover. Also, where do hypocoristics fit into these ratios? Some at least of those listed under “Tom Murphy” are “Thomas Murphy” on their birth certificate.